Display screen or portion thereof with transitional graphical user interface



FIG. 1 is a front view of the first image in a sequence for a displayscreen or portion thereof with transitional graphical user interfaceshowing our new design according to a first embodiment;

FIG. 2 is the second image thereof;

FIG. 3 is the third image thereof;

FIG. 4 is a front view of the first image in a sequence for a displayscreen or portion thereof with transitional graphical user interfaceshowing our new design according to a second embodiment;

FIG. 5 is the second image thereof; and,

FIG. 6 is the third image thereof.

The outer perimeter shown in broken lines in the figures illustrates adisplay screen or portion thereof and forms no part of the claimeddesign. The remaining broken lines in the figures illustrate portions ofthe graphical user interface that form no part of the claimed design.

The appearance of the transitional image sequentially transitionsbetween the images shown in FIGS. 1-3 and 4-6, respectively. The processor period in which one image transitions to another image forms no partof the claimed design.

CLAIM The ornamental design for a display screen or portion thereof withtransitional graphical user interface, as shown and described.